drm/i915/ppgtt: Break loop in gen8_ppgtt_clear_range failure path

If for some reason [1], the page directory/table does not exist, clear_range
would end up in an infinite while loop.

Introduced by commit 06fda602dbca ("drm/i915: Create page table allocators").

[1] This is already being addressed in one of Mika's patches:
http://mid.gmane.org/1432314314-23530-17-git-send-email-mika.kuoppala@intel.com

Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: stable@vger.kernel.org
Reported-by: John Harrison <john.c.harrison@intel.com>
Signed-off-by: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 619dad1b23863716972a23b12226b16af533a068..9daa2883ac186f73c64baa40ba61aadfd0a94c9a 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -516,17 +516,17 @@ static void gen8_ppgtt_clear_range(struct i915_address_space *vm,
                struct page *page_table;
 
                if (WARN_ON(!ppgtt->pdp.page_directory[pdpe]))
-                       continue;
+                       break;
 
                pd = ppgtt->pdp.page_directory[pdpe];
 
                if (WARN_ON(!pd->page_table[pde]))
-                       continue;
+                       break;
 
                pt = pd->page_table[pde];
 
                if (WARN_ON(!pt->page))
-                       continue;
+                       break;
 
                page_table = pt->page;